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  »  New  An ultimate transformer for narrow bandwidth?..  Re: ...apply similar tactics to the power supply......  Melquiades Amplifier  Forum     14  86220  02-03-2005
  »  New  Ultimate HF output transformer?..  Leads to further air core heads...  Melquiades Amplifier  Forum     7  71466  07-14-2005
  »  New  The one-stage Melquiades...  Tubes vs. Speakers vs. FR...  Melquiades Amplifier  Forum     73  458879  04-21-2007
  »  New  6 Channel Version of Super Melquiades..  The first Milq screw up....  Melquiades Amplifier  Forum     131  869508  08-08-2007
10-21-2005 Post does not mapped to Knowledge Tree
Romy the Cat


Boston, MA
Posts 9,540
Joined on 05-28-2004

Post #: 1
Post ID: 1540
Reply to: 1540
Fun with transformers?

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It is interesting… I have a very precisely calibrated ¼db resolution AV meter and I decided juts for fan to see what the channels of Super Milq will do in the real life. I kept my Mocondo, along with the woofer towers connected to the Super Milq’s 3 channels, and juts ran the high impedance AV meters parallel to the loads of the each channel. I run the amp from my function generator with 1V at input (it is not full power but it was max that I was able to tolerate being in the same room, it was very loud!). I had the Super Milq rolling off at ¼db at 7.65Hz and the bottom and 23.455kHz at the top. I wonder: I have one spare full range Milq, the first one ever was built, and I would like to try a different transformer on it as a full range amp? Are any reedy to go transformers out there that might handle the real full range, at full 15W, down to 12-15Hz?

The Cat


"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche
03-29-2006 Post does not mapped to Knowledge Tree
Resorob
Posts 1
Joined on 03-07-2006

Post #: 2
Post ID: 2263
Reply to: 1540
Re: Fun with transformers?
Hi Romy,

I realise that this is a very old post, but you might want to take a look over here=>> http://www.valvediy.com/simplexpg1.html

The article can be downloaded as PDF, the writer Ari Polisois developped a new kind of transformer called SC OPT "Self Compensating Out Put Transformer". This could be a unique transformer and  maybe it can handle the full range at full power. In any case I have never seen a similar transformer.

The SC OPT has three windings, primary, secundary and tertiary the tertiary winding compensates for the dc current running through the transformer to the power tubes. Since this magnetism is compensated for, practically the whole core is available for the music signal, maybe Ari Polisois can better explain. Should you want it you can reach him at:

A2Belectronic@wanadoo.fr

Regards,

Rob.

03-30-2006 Post does not mapped to Knowledge Tree
Romy the Cat


Boston, MA
Posts 9,540
Joined on 05-28-2004

Post #: 3
Post ID: 2267
Reply to: 2263
Ari Polisois’ Direct-Coupled Simplex

 Resorob wrote:
I realise that this is a very old post, but you might want to take a look over here=>> http://www.valvediy.com/simplexpg1.html

The article can be downloaded as PDF, the writer Ari Polisois developped a new kind of transformer called SC OPT "Self Compensating Out Put Transformer". This could be a unique transformer and  maybe it can handle the full range at full power. In any case I have never seen a similar transformer.

The SC OPT has three windings, primary, secundary and tertiary the tertiary winding compensates for the dc current running through the transformer to the power tubes. Since this magnetism is compensated for, practically the whole core is available for the music signal, maybe Ari Polisois can better explain. Should you want it you can reach him at:
Rob, thanks. I have seen the Ari’s SET a few years back and I believe it should be somewhere in my links.

I did not see anything special about the out transformer, at lease in the papers that I read. Also, even if I did see it I’m not convinced that I would be qualified to assess the effectiveness if what Ari offers as it all should be heard.

Regarding Ari’s amp. I would do the input choke filters and beef up the power transformer in the output stage. I do not know how about the Ari’s driver stage. The tube he uses is fine tube but how 2 series halfs of this tube might sound? It should be tried and assessed. Unfortunately Ari does not writhe a lot about sound. It would be interesting if Ari try in there one Melquiades’ 5E5P. Also, Ari for whatever reasons chose to drive the 6C33c too hard. i do not know why but I presume he has his reasons…

Anyhow, the most important subject in the Simplex amplifier is the Direct-Coupling. This is quite competed question and it is not as simple as people usually fill. The logic that the best capacitors are not capacitors is not really applicable in this case, although it is true and the quality and type of the coupling capacitors are hugely important.

You see, there is something that I call: the “Tactical Sound”. The Tactical Sound is the separate inflictions of sounds the different caps inflict to Sound. Also, there is something that I call the “Strategic Sound”. The “Strategic Sound” is not depends from “the sounds” and more relates to the robustness and function of Sound in it’s entirety. The “Strategic Sound” very little depends from the coupling caps or from any other sounds polishing mechanisms but rather form the general topology of an amplifier. The coupling caps unquestionably affect sound negatively (and this why the Melquiades uses the Cubes 950) but the coupling caps (or any other DC blocking between the stages) does affect the “Strategic Sound” in very positive way.

I am not convinced in what I am proposing as I am sure that there are different direct-coupled implementations and I did nit heard all of them. A few years ago Vladimir Lamm published a quite interesting article in Russian magazine about his M1.1 amplifier where he mentioned about his research in the subject of direct coupling and his observations about the negative effect it had to Sound. That article made me to think about it further and to look very careful at my very certain reactions when I hear the two stages direct couple amps. Generally I would concur what Lamm proposed in his article but here is the problem: all my auditions were not “clean” experiments, methodologically speaking. I heard a few (perhaps 3-4 amps) but all of them were “built and closed” amps and there are a lot of other thing in those amps that might very much offset the auditable results. I never had an opportunity to have two stages and then, by building different PS supplies to compare the Tactical Sound and Strategic Sound of direct coupled, C- coupled and perhaps the transformer- coupled.

I know some people who do it and they shared their observations with me. I was not pleased with the level of those assessments as people told me the stories about the Sound but not about Sound. So, the main question in the Ari’s Simplex is: was the direct-coupling a good or bad thing. Unfortunately Ari did not provide any reference point in order to demonstrate the level of his assessments. All that he said was that the Simplex has an “Excellent sound” and it is defiantly too simple statement.

Rgs,
Romy the Cat


"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche
03-30-2006 Post does not mapped to Knowledge Tree
AnonymousUser
Posts 19
Joined on 11-27-2004

Post #: 4
Post ID: 2268
Reply to: 2267
Re: Ari Polisois’ Direct-Coupled Simplex
Rob and Romy the Cat,
Thank you for inviting me to discuss this subject. Allow me to reply only to the main points raised, due to the present overload of work. However I will try to answer, later, to any specific question on the subject.
First : - My philosophy on sound reproduction valve amplifiers ( my knowledge on solid state is very limited and I rely on my son, who is a young electronic engineer, for help) is very simple : it is based on the logical statement that what is simple is easier and what is easier generates less mistakes.
Therefore, I wrote an article for Valve e-zine, some years ago, after patenting (just an elementary certificate named here, in France, "Certificat d'utilité") my D.C.M.B. system, also described as absolute direct coupling all-the-way of the musical signal path.  Some objections were made on this statement because the signal crosses a set of capacitors in the power supply. Sorry, there is not much I can do about that, except suggest to use batteries or some other electric power source not using capacitors.
At the beginning I used prestigeous output transformers, such as the Plitrons, designed by Menno van der Veen and Brian Sowter's OPTs, but when a friend of mine asked me to design a high power amplifier ( 50 Watts ) to drive his Greek-pi AR enclosures ( wonderful but very stiff) and specified he wanted it in single ended layout and DCMB, I realized I could never find a SE output transformer to handle such a power.
Second - I revised my magnetic circuits knowledge (dusty because it went back 30 years before, when I studied it at the Ecole Central de TSF of Paris, with an excellent teacher : Lucien Chrétien.
After reading several books ( I could mention them but I do not know if I am allowed - in another Forum a long message I had written was rejected because I mentioned a good author and his book and I got discouraged and frustrated Wink, I understood why there is a gap in the SE output transfomers and the consequences of this compromise. From there I imagined several solutions and experimented them, until I came close to a good one, the SC-OPT (presented at the AES Convention held in Barcelona May 2005).
Third - Life is hard for individual researchers. After drying my savings to achieve acceptable results and obtain the corresponding patents) I received some justified objections, both on the Direct Coupling Modulated Bias System ( see www.audiodesignguide.com - bottom of the banners list, and Glass Audio 17 novel projects and Plitron's site ) mentioning Loftin and White's amplifier, and on the SC-OPT . In reality, some solutions look similar on the paper (schematics) but not in practice, and this was my case. A small detail sometimes makes a huge difference.
Fourth - What DCMB has achieved ?  a) simplicity  b) speed   c) no frequency discrimination  d) wider frequency range  e) suppression of the PSU noises ( I owe this claim to a Canadian friend who noticed it first), f) single point idle current adjustment and g) (under experiment) possibility of modifying the sound stage.
Regarding the OPT, just one, big, step forward : you can now build SE amplifiers with unlimited power (better said : up to the physical limits of an output transformer) as opposed to the 10 max 30 Watts currently accepted.
                               Sorry for this long story but it explains what follows :
I cannot issue any certificate on the quality of the sound. I have, of course, testimonials, but I am not ready to repeat them ( in the past I quoted them several times, but the skepticals remained such ). 
As a consequence, those who want to check the DCMB and spare some time and money, as well as curiosity or faith, are welcome to send me an e.mail at A2BElectronic@wanadoo.fr and I will do my best to supply more information and advices.
Alternatively, they can build the 1940-1960 models of amplifiers, changing one or two components here and there, to refine the sound. Just make sure that the qualities claimed for these products are real and not "commercial".
Good luck.
Ari Polisois
PS - The SC-OPT works satisfactorily only with low internal resistance valves ( lower than 250 ohms).
There are however two more generations under test, based on alternative solutions, that are expected to solve the problem to such a degree that even penthodes will be suitable for single ended layouts.
03-30-2006 Post does not mapped to Knowledge Tree
Romy the Cat


Boston, MA
Posts 9,540
Joined on 05-28-2004

Post #: 5
Post ID: 2270
Reply to: 2268
“Easy come, easy go” sound...

 AnonymousUser wrote:
Fourth - What DCMB has achieved ?  a) simplicity  b) speed   c) no frequency discrimination  d) wider frequency range  e) suppression of the PSU noises ( I owe this claim to a Canadian friend who noticed it first), f) single point idle current adjustment and g) (under experiment) possibility of modifying the sound stage.
Ari, what actually I would be more queries in the case of your amp:

a) How whatever you/we “speed” relates with whatever we call “harmonic structure” and how realistic the harmonic pattern of your amplifier is

b) I do not know what “no frequency discrimination” is and I do not know at which power you took your frequency sweep. Whatever it was a regular SET, according to my believe, can not work properly full range and requires a DSET configuration

c) How naturalistic the bass and upper bass in your amp. Usually the direct-coupled designs (similar to OTLs) have some strangeness in there and produce overly open and “overly transparent” "melody range". In this case when I say overly transparent I did not mean “quality” but rather the “listener’s transparency”.

It is hard to explain what it the “listener’s transparency” in bass because the idiots who write for audio publications have crated a huge amount of buzz-words and bogus audio definitions but none of those that are important. By suggesting the listener’s transparency in the DC-coupling devises I mean very different concept then it might derive from the words. You see, when we listen music then music has some fulfilling effect. I mean the phrases, melodies, or juts the notes of this sequence is absorbed by out awareness and become our more or less permanent sensorial baggage. The question is if the audio processing topology coil affect the duration of that baggage. What I detected that when I listened the direct-coupled designs I got immediately impressed by the LF harmonic but at the same time I dot immediately “discharged” with my sensorial feeling as soon the music was over. I had very short accumulative memory of my experiences after I head the direct-coupled and the long-term musical fulfillment was very-very challenged. I call it the “listener’s transparency” as music become too transparent for a listener’s awareness and does not hold itself in a listener mind, as least in my mind. 

This why I am very withhold with the two stages, direct-coupled amplifiers…. As least they require a very careful listening assessment to make sure that they do not do their “easy come, easy go” sound…

Rgs,
Romy the Cat


"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche
03-31-2006 Post does not mapped to Knowledge Tree
AnonymousUser
Posts 19
Joined on 11-27-2004

Post #: 6
Post ID: 2271
Reply to: 2270
Re: “Easy come, easy go” sound...
Dear Romy,
Assuming that your questions are "honest" ones ( I have no reason to believe they are traps, like it happened to me before with a certain Mr. Thor), I will give you "honest" answers, hoping that our dialogue will be of some interest to the audiophile community.
Foreword : it will not be easy for you and me to meet on a common ground, because I have the feeling (sorry, I am new to your Forum) that you judge in terms of "sound emotions" , which is not wrong, after all, and I judge in terms of "amplifier structure" . My reasoning will be more clear after you see my answers, but, in any case, it is based on : make a good sound reproduction electrical device and the result will not be too far from the live one (exactly the same is impossible, I believe).
Your query a) : "speed" and "harmonic structure/pattern" .
By "speed" I mean the response of the amplifier to transients. I have some nice instruments in my personal laboratory but not all the ones I would like to possess (a matter of budget, family needs, etc.). I mentioned this characterisics for two reasons: a1) how could a circuit be faster that a driver stage of the concertina/williamson" type and a no-capacitor coupling between the terminals of the anode load of the second stage of the driver and the pair "Grid/cathode" of the power tube ?   a2) I have a dozen people who said so, in different ways ( quoting some words: fast, dynamic, aggressive). These statements come close to your way of judging the reproduced sound, I think.
Sorry again, but I cannot supply measured data. I had a "slew-rate" meter software fitted to my former
PC, but, probably due to a mistake, it failed and also "burned" my computer. So, now, as stated, I can only rely on my observing the schematics and on other people's judgments. By the way, some of them are musicians, some skilled electronic engineers, and some both. Among the younger judges, my 19 year old daughter, who, exceptional case, likes Beethoven, Vivaldi, Pavarotti and Gershwin as well as Alicia Keys' songs.
Regarding the harmonic structure, I can only measure the THD with my HP 334A distortion analyzer, and I rely on the fact that, in Single ended amplifiers, the odd harmonics content is very weak, compared to the second harmonic one. The latter, as many people state, is well accepted by the ear.
I add to that something you might not agree with: although I know that, in an average size listening room (living room, TV room or other) 5 watts, with 95-100dB enclosures, are more than enough, I prefer to build a 30 W amplifier that showed 6,5 % THD at full output, and listen at moderate level ( 5-7 W ) in order to have 0,5 % THD, of which 0,05 % of nasty odd harmonics ( as found in bigger quantities in push-pull amplifiers). Have you had a chance to look at the "Simplex" "Duplex" or "King" (the latter is a 3X6C33C-B per channel, delivering 50W in single ended - see AudioXpress July 2004) schematics ?
Your Query b) By frequency discrimination I intend the difference in the signals' amplitudes transferred from the driver to the power tube, at different frequencies. In typical R/C couplings, this is due to the presence of the blocking capacitor, worsened by the Miller Effect. The same problem exists with the DCMB, but to a much lesser extent ( it depends of course on the circuit layout and components used).
Your Query c) This is the most difficult question. I think you are right with your "bass sensation feeling" and I am at a loss to give you a decent answer. All I can say is that it happened also to me to listen to a
couple of amplifiers with a "disturbing bass effect" . Let me add that this does not happen with my amplifiers ( I have built about 20 different ones), except in a couple of cases ( mainly due to a mismatch between power tube and impedance of the load, or uncorrect biasing and/or supply voltage) that I immediately discarded or solved .
Transparency : In my condition ( meaning age ) I must rely on two facts:
  - other people's reactions ( to avoid polite statements I make listening sessions with two or even three  
    different amplifiers and get more genuine responses with preferences and corresponding reasons)
  - Because the lisening sessions cannot be too long, I sit and listen myself , for hours, different kinds of
    music, paying much attention to the "fatigue" or "boring" sensations. In some happy cases, the more 
    I listened, the more I wanted to, but most of the time I was "satisfied" but absolutely not "tired".
To conclude, I think you understood that I am particularly fond of the Single ended layout and have spent much time in boosting its qualities ( I particularly like the way it respects the slightest details of the music - some of my friends can listen to the fingers touching the instruments: pianos, and other).
Nice talking to you, Romy, but do not bother to criticize, if it is constructive.
Ari.

03-31-2006 Post does not mapped to Knowledge Tree
Romy the Cat


Boston, MA
Posts 9,540
Joined on 05-28-2004

Post #: 7
Post ID: 2272
Reply to: 2271
An amplifier is not a subject but a service..

Ari,

I do not think that we recognize the process of “audio designing” as the identical actively. It looks as you peruse to design an amplifier (for instance) as a conceptually well operating system where a set of deferential abstractly-measurable values would complies with some sort of notion that you have. I do not see the things this way. To me an amplifier is not a subject but a service, and this is how I approach to the process of an amplifier designing and an amplifier assessment. To me there is not such a thing as “speed” vs. “harmonics” and from the place where I stay the harmonic patters is measurable but quantifiably it is not interpretable parameter.

What I mean that “a result” might not be assessed with its contribution to the purpose and to the meaning of “the result”. A result is like a”tempo” in music. There is no absolute or predefined tempos, ever the reface to metronome is worthless because there was a number of the different metronome scales. The “correct” tempo is not something fixed but it is “moderated” by very many variables and in the end, result the human practice, tighten to the many not quantifiable reasons, set it to be “right”.

Well, this I sensed from what you have written and it might be a separate subject… If you wish we might continue it in other more appropriate forums of the site.

Meanwhile this specific forum is dedicated to help those crassly people who are wiling to build the Melquiades and we wonder off the subject. I think that your Simplex amp is in the Melquiades alley and it is great that people who might contemplate to build the two stages with 6C33C would have a change to see multiple options and multiple view valuable

Rgs,
Romy the Cat

PS: Nope, I am not familiar nether with your 3X6C33C amp nor with Duplex


"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche
03-31-2006 Post does not mapped to Knowledge Tree
AnonymousUser
Posts 19
Joined on 11-27-2004

Post #: 8
Post ID: 2273
Reply to: 2272
Re: An amplifier is not a subject but a service..
OK Romy,
Compared to you I am pragmatic, but after all what matters is the emotion you get from an amplifier, the latter being considered as a musical instrument with a specific personality.
You can enjoy listening to a violin, a guitar, a banjo or a mandoline.
I'll have a look at the other forums.
Have a nice week end,
Ari.
Page 1 of 1 (8 items) Select Pages: 
   Target    Threads for related reading   Most recent post in related threads   Forum  Replies   Views   Started 
  »  New  An ultimate transformer for narrow bandwidth?..  Re: ...apply similar tactics to the power supply......  Melquiades Amplifier  Forum     14  86220  02-03-2005
  »  New  Ultimate HF output transformer?..  Leads to further air core heads...  Melquiades Amplifier  Forum     7  71466  07-14-2005
  »  New  The one-stage Melquiades...  Tubes vs. Speakers vs. FR...  Melquiades Amplifier  Forum     73  458879  04-21-2007
  »  New  6 Channel Version of Super Melquiades..  The first Milq screw up....  Melquiades Amplifier  Forum     131  869508  08-08-2007
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